Skip to main content
. 2006 Apr 3;116(4):916–928. doi: 10.1172/JCI27203

Figure 10. A model for induction of regulatory DCs, macrophages, and immune tolerance by yeast zymosan.

Figure 10

Our previous work suggests that Pam-3-cys, which signals DCs through TLR2, induces robust IL-10 and IL-6 but little IL-12(p70) (13, 14). Induction of IL-10 and impaired IL-12(p70) production appear to be critically regulated by ERK activation, which results in the phosphorylation and stabilization of c-Fos, a repressor of IL-12 (13, 14). Such a DC cytokine profile appears to bias toward the Th2 pathway. In the present paper, we demonstrate that zymosan signals to DCs via both TLR2 and dectin-1, inducing the expression of abundant IL-10 but little IL-12(p70) or IL-6. Unlike the case with Pam-3-cys, impairment of IL-12(p70) and induction of c-Fos are not dependent on c-Fos. Induction of IL-10 represses the induction of proinflammatory cytokines, including IL-12, IL-6, and TNF-α. In addition to these effects on DCs, zymosan also induces biologically active TGF-β in macrophages. In this case, the robust induction of IL-10 and TGF-β coupled with impaired induction of IL-6 and IL-12(p70) appears to induce immunological tolerance.